JP2013118366A - Support, lithographic apparatus and device manufacturing method - Google Patents

Abstract

A support is provided that takes measures to reduce bending of a substrate during loading.
A support for an object having a support surface configured to support the object, the support surface including a main portion and a movable portion, the movable portion of the support surface extending in a retracted position and extending. In the retracted position, the movable part of the support surface is substantially in the same plane as the main part of the support surface, and in the extended position, the movable part of the support surface is the main part of the support surface. Projects from the plane of the part.
[Selection] Figure 2

Description

  The present invention relates to a support, a lithographic apparatus, and a device manufacturing method.

  A lithographic apparatus is a machine that applies a desired pattern onto a substrate, usually onto a target portion of the substrate. A lithographic apparatus can be used, for example, in the manufacture of integrated circuits (ICs). In that case, a patterning device, also referred to as a mask or a reticle, may be used to generate a circuit pattern formed on an individual layer of the IC. This pattern can be transferred onto a target portion (eg including part of, one, or more dies) on a substrate (eg a silicon wafer). Usually, the pattern is transferred by imaging on a radiation-sensitive material (resist) layer provided on the substrate. In general, a single substrate will contain a network of adjacent target portions that are successively patterned. Known lithographic apparatus include a so-called stepper that irradiates each target portion by exposing the entire pattern onto the target portion at once, and simultaneously scanning the pattern in a certain direction ("scan" direction) with a radiation beam. Also included are so-called scanners that irradiate each target portion by scanning the substrate parallel or antiparallel to this direction. It is also possible to transfer the pattern from the patterning device to the substrate by imprinting the pattern onto the substrate.

  [0003] The machine may be such that a liquid (eg, water) having a relatively high refractive index fills the space between the final element of the projection system and the substrate. In one embodiment, the liquid is distilled water, although other liquids can be used. Other fluids, particularly wetting fluids, incompressible fluids, and / or fluids having a refractive index higher than air, desirably higher than water, may be suitable. A gas-free fluid is particularly desirable. The point of this is to allow imaging of smaller features because the exposure radiation has a shorter wavelength in the liquid. (The effect of the liquid may be considered to increase the effective numerical aperture (NA) of the system and also increase the depth of focus. Other immersion liquids have also been proposed, in which solid particles (E.g. quartz) includes liquids with suspended water or nanoparticle suspensions (e.g. particles with a maximum dimension of up to 10 nm), which have the same or the same refractive index as the liquid in which they are suspended. Other liquids that may or may not be suitable include hydrocarbons such as aromatics, fluorinated hydrocarbons, and / or aqueous solutions.

  [0004] The patterning device may be used to generate other patterns (eg, color filter patterns or dot matrices) instead of circuit patterns. The patterning device may comprise a patterning array that includes an array of individually controllable elements that generate a circuit or other applicable pattern instead of a conventional mask. The advantage of such a “maskless” system compared to conventional mask-based systems is that patterns can be provided and / or modified more quickly and at a lower price.

  [0005] Accordingly, the maskless system includes a programmable patterning device (eg, spatial light modulator, contrast device, etc.). The programmable patterning device is programmed (eg, electronically or optically) to form a desired patterned beam using an array of individually controllable elements. Examples of programmable patterning devices include micromirror arrays, liquid crystal display (LCD) arrays, grating light valve arrays, and the like.

  [0006] As disclosed in PCT Patent Application Publication No. WO2010 / 032224, which is incorporated herein by reference in its entirety, the modulator replaces the exposure area of the substrate with a desired pattern, instead of a conventional mask. May be configured to expose a plurality of beams modulated in accordance with. The projection system is configured to project the modulated beam onto the substrate and may include a lens array to receive the plurality of beams. The projection system is configured to project the modulated beam onto the substrate and may include a lens array to receive the plurality of beams. The projection system may be configured to move the lens array relative to the modulator during exposure of the exposure area.

  [0007] The lithographic apparatus may be an extreme ultraviolet (EUV) apparatus that uses extreme ultraviolet light (eg, having a wavelength in the range of about 5-20 nm).

  [0008] In one embodiment of the lithographic apparatus, the substrate is loaded onto the support surface of the substrate table by a robot that holds the substrate on the bottom side of the substrate. A plurality of pins (hereinafter “e-pins”) are provided on the substrate table to facilitate loading of the substrate on a substantially horizontal support surface. For example, three e pins may be provided. The e-pin is movable between an extended position where the upper end of the e-pin extends above the substrate table and a contracted position where the upper end of the e-pin is contracted to the substrate table.

  [0009] During substrate loading on the substrate table, the robot loads the substrate onto the e-pins in the extended position. Since the substrate is received on an e-pin that extends above the support surface, the robot can be pulled out leaving the substrate on the e-pin. The e-pin can then be moved to the retracted position and the substrate can be placed on the support surface.

  [0010] The shape of the substrate during the loading sequence is defined by the gravity sink of the substrate. Other effects, such as the effect of a gas (eg, air) flowing under the substrate, can also affect the shape of the substrate. While the substrate is in contact with the substrate table, the freedom to manipulate the final substrate shape is limited.

  [0011] A substrate having an increased size is handled in a lithographic apparatus. Currently, substrate sizes having a width of up to 300 mm are used in lithography processes. It is desirable to increase the width (eg, diameter) of the substrate, for example, to a diameter of about 450 mm. These larger substrates have a smaller thickness to width ratio, resulting in reduced bending stiffness. As a result, the substrate may have a greater gravity deflection with respect to e-pins in the extended position, which may in essence lead to larger substrate load grid errors and potential overlay errors. Furthermore, the e-pins may need to have a larger surface area to support an increased weight of the substrate compared to, for example, a 300 mm diameter substrate. This can lead to a decrease in flatness when the substrate is clamped to the support (because in that state the substrate is not supported by the e-pin).

  [0012] For example, it is desirable to provide a support that takes measures to reduce bending of the substrate during loading.

  [0013] According to one aspect of the invention, a support for an object is provided comprising a support surface configured to support the object. The support surface includes a main portion and a movable portion, the movable portion of the support surface being movable between a retracted position and an extended position, wherein the movable portion of the support surface is in contact with the main portion of the support surface. Adapted to be in substantially the same plane, in the extended position, the movable part of the support surface protrudes from the plane of the main part of the support surface.

  [0014] According to one aspect of the present invention, a support for an object, disposed to form a support surface configured to support the object, and a multi-sided side surface when viewed from above, and An elongate movable part that is movable between a retracted position and an extended position, wherein the retracted position is adapted such that the upper end of the movable part is at or below the plane of the main part of the support surface; In the extended position, a support is provided comprising an elongate movable portion, the upper end of the movable portion protruding from the plane of the main portion of the support surface.

  [0015] According to one aspect of the invention, there is provided a device manufacturing method that includes projecting a patterned beam of radiation onto a substrate supported by a support surface. The support surface includes a main portion and a movable portion, the movable portion of the support surface being movable between a retracted position and an extended position, wherein the movable portion of the support surface is in contact with the main portion of the support surface. Adapted to be in substantially the same plane, in the extended position, the movable part of the support surface protrudes from the plane of the main part of the support surface.

[0016] Some embodiments of the invention will now be described, by way of example only, with reference to the accompanying schematic drawings. In these drawings, the same reference numerals indicate corresponding parts.
[0017] Figure 1 depicts a lithographic apparatus according to one embodiment of the invention. [0018] FIG. 2 schematically illustrates a support according to one embodiment in plan view. FIG. 3 shows a cross-sectional view through line III of FIG. 2 when in the retracted position. [0020] FIG. 4 shows a cross-sectional view through line III of FIG. 2 in the extended position. FIG. 5 shows a cross-sectional view through line V of FIG. FIG. 6 is a detailed plan view of a part of the movable part of the embodiment of FIG. [0023] FIG. 7 illustrates a movable part of one embodiment. [0024] FIG. 8 schematically illustrates a support according to one embodiment in plan view.

[0025] Figure 1 schematically depicts a lithographic apparatus according to one embodiment of the invention. This device
An illumination system (illuminator) IL configured to condition a radiation beam B (eg UV radiation or DUV radiation);
A support structure (e.g. a mask table) constructed to support the patterning device (e.g. mask) MA and coupled to a first positioner PM configured to accurately position the patterning device according to certain parameters MT)
A substrate table (e.g. a wafer table) constructed to hold a substrate (e.g. resist-coated wafer) W and connected to a second positioner PW configured to accurately position the substrate according to certain parameters ) WT,
A projection system (eg a refractive projection lens system) configured to project a pattern imparted to the radiation beam B by the patterning device MA onto a target portion C (eg comprising one or more dies) of the substrate W; PS.

  [0026] The illumination system includes refractive, reflective, catadioptric, magnetic, electromagnetic, electrostatic, or other types of optical components to induce, shape, or control radiation, Alternatively, various types of optical components such as any combination thereof can be included.

  [0027] The support structure MT holds the patterning device in a manner that depends on the orientation of the patterning device, the design of the lithographic apparatus, and other conditions, such as whether or not the patterning device is held in a vacuum environment. The support structure can hold the patterning device using mechanical, vacuum, electrostatic or other clamping techniques. The support structure may be, for example, a frame or table that can be fixed or movable as required. The support structure may ensure that the patterning device is at a desired position, for example with respect to the projection system. Any use of the terms “reticle” or “mask” herein may be considered synonymous with the more general term “patterning device.”

  [0028] The term "patterning device" as used herein refers to any device that can be used to provide a pattern in a cross section of a radiation beam so as to create a pattern in a target portion of a substrate. Should be interpreted widely. It should be noted that the pattern imparted to the radiation beam may not exactly match the desired pattern in the target portion of the substrate, for example if the pattern includes phase shift features or so-called assist features. . Typically, the pattern applied to the radiation beam will correspond to a particular functional layer in a device being created in the target portion, such as an integrated circuit.

  [0029] The patterning device may be transmissive or reflective. Examples of patterning devices include masks, programmable mirror arrays, and programmable LCD panels. Masks are well known in lithography and include mask types such as binary, alternating phase shift, and halftone phase shift, as well as various hybrid mask types. One example of a programmable mirror array uses a matrix array of small mirrors, and each small mirror can be individually tilted to reflect the incoming radiation beam in various directions. The tilted mirror patterns the radiation beam reflected by the mirror matrix.

  [0030] As used herein, the term "projection system" refers to a refractive, reflective, appropriate for the exposure radiation used or for other factors such as the use of immersion liquid or vacuum. It should be construed broadly to encompass any type of projection system including catadioptric, magnetic, electromagnetic, and electrostatic optics, or any combination thereof. Any use of the term “projection lens” herein may be considered as synonymous with the more general term “projection system”.

  [0031] As shown herein, the lithographic apparatus is of a transmissive type (eg employing a transmissive mask). Further, the lithographic apparatus may be of a reflective type (for example, one employing the above-described programmable mirror array or one employing a reflective mask).

  [0032] The lithographic apparatus may be of a type having two or more tables (or stages or supports), for example, two or more substrate tables or a combination of one or more substrate tables and one or more sensors or measurement tables. It may be. In such “multi-stage” machines, additional tables can be used in parallel, or one or more tables are used for exposure while a preliminary process is performed on one or more tables. You can also A lithographic apparatus may have two or more patterning devices (or stages or supports) that can be used in parallel in a manner similar to a substrate, sensor and / or measurement table.

  In addition, the lithographic apparatus is of a type that can cover at least a part of a substrate with a liquid (eg, water) having a relatively high refractive index so as to fill a space between the projection system and the substrate. There may be. An immersion liquid may also be added to another space in the lithographic apparatus (eg, between the mask and the projection system). Immersion techniques are well known in the art for increasing the numerical aperture of projection systems. The term “immersion” as used herein does not only mean that a structure, such as a substrate, must be submerged in the liquid, but also during the exposure the projection system and the substrate and / or mask. This means that liquid can be placed between the two. This may or may not include submerging a structure such as a substrate in the liquid. The reference sign IM indicates where an apparatus for performing immersion techniques can be placed. Such an apparatus may include a supply system for immersion liquid and a sealing member for containing liquid in the region of interest. Such an apparatus may optionally be configured such that the substrate table is completely covered by immersion liquid.

  [0034] Referring to FIG. 1, the illuminator IL receives a radiation beam from a radiation source SO. For example, if the radiation source is an excimer laser, the radiation source and the lithographic apparatus may be separate components. In such a case, the radiation source is not considered to form part of the lithographic apparatus, and the radiation beam is directed from the radiation source SO to the illuminator IL, eg, a suitable guiding mirror and / or beam extractor. Sent using a beam delivery system BD that includes a panda. In other cases the source may be an integral part of the lithographic apparatus, for example when the source is a mercury lamp. The radiation source SO and the illuminator IL may be referred to as a radiation system, together with a beam delivery system BD if necessary.

  [0035] The illuminator IL may include an adjuster AD for adjusting the angular intensity distribution of the radiation beam. In general, at least the outer and / or inner radial extent (commonly referred to as σ-outer and σ-inner, respectively) of the intensity distribution in the illuminator pupil plane can be adjusted. In addition, the illuminator IL may include various other components such as an integrator IN and a capacitor CO. By adjusting the radiation beam using an illuminator, the desired uniformity and intensity distribution can be provided in the cross section of the radiation beam. Like the radiation source SO, the illuminator IL may or may not be considered to form part of the lithographic apparatus. For example, the illuminator IL may be an integral part of the lithographic apparatus or may be a separate component from the lithographic apparatus. In the latter case, the lithographic apparatus may be configured such that the illuminator IL is placed thereon. Optionally, the illuminator IL is removable and may be provided separately (eg, by the lithographic apparatus manufacturer or another supplier).

  [0036] The radiation beam B is incident on the patterning device (eg, mask) MA, which is held on the support structure (eg, mask table) MT, and is patterned by the patterning device. After passing through the patterning device MA, the radiation beam B passes through the projection system PS, which focuses the beam on the target portion C of the substrate W. The substrate table is used, for example, to position various target portions C in the path of the radiation beam B using a second positioner PW and a position sensor IF (eg, interferometer device, linear encoder, or capacitive sensor). The WT can be moved accurately. Similarly, using the first positioner PM and another position sensor (not explicitly shown in FIG. 1), for example after mechanical removal from the mask library or during scanning, the patterning device MA is irradiated with the radiation beam. It is also possible to accurately position with respect to the path B. Usually, the movement of the support structure MT can be achieved using a long stroke module (coarse positioning) and a short stroke module (fine positioning) that form part of the first positioner PM. Similarly, movement of the substrate table WT can also be achieved using a long stroke module and a short stroke module that form part of the second positioner PW. In the case of a stepper (as opposed to a scanner) the support structure MT may be connected only to a short stroke actuator or may be fixed. Patterning device MA and substrate W may be aligned using patterning device alignment marks M1 and M2 and substrate alignment marks P1 and P2. In the example, the substrate alignment mark occupies the dedicated target portion, but the substrate alignment mark can also be placed in the space between the target portion (these are known as scribe line alignment marks). Similarly, if multiple dies are provided on the patterning device MA, the patterning device alignment marks may be placed between the dies.

[0037] The example apparatus can be used in at least one of the modes described below.
1. In step mode, the entire pattern applied to the radiation beam is projected onto the target portion C at once (ie, a single static exposure) while the support structure MT and the substrate table WT remain essentially stationary. Thereafter, the substrate table WT is moved in the X and / or Y direction so that another target portion C can be exposed. In step mode, the maximum size of the exposure field limits the size of the target portion C imaged during a single static exposure.
2. In scan mode, the support structure MT and the substrate table WT are scanned synchronously while a pattern imparted to the radiation beam is projected onto a target portion C (ie, a single dynamic exposure). The speed and direction of the substrate table WT relative to the support structure MT can be determined by the (reduction) magnification factor and image reversal characteristics of the projection system PS. In the scan mode, the maximum size of the exposure field limits the width of the target portion during single dynamic exposure (non-scan direction), while the length of the scan operation determines the height of the target portion (scan direction). Determined.
3. In another mode, with the programmable patterning device held, the support structure MT remains essentially stationary and the substrate table WT is moved or scanned while the pattern attached to the radiation beam is targeted. Project onto part C. In this mode, a pulsed radiation source is typically employed, and the programmable patterning device can also be used after each movement of the substrate table WT or between successive radiation pulses during a scan as needed. Updated. This mode of operation can be readily applied to maskless lithography that utilizes programmable patterning device, such as a programmable mirror array of a type as described above.

  [0038] Combinations and / or variations on the above described modes of use or entirely different modes of use may also be employed.

  [0039] The lithographic apparatus comprises a substrate table WT. The upper part of the substrate table WT is shown in more detail in FIGS. FIG. 2 is a plan view of one embodiment of the support 1 of the substrate table WT. The support 1 is configured to support an object, and supports the substrate W in the case of a lithographic apparatus.

  The support 1 includes a support surface 20. The support surface 20 is configured to support the substrate W on the substrate table WT. The support surface 20 may be planar, but by a large number of individual bars (projections, shown as black dots in FIG. 2) or other objects extending from the top surface 25 of the body 22 to the support height. It may be defined. The protrusions may have a pitch of about 1.5 to 3.0 mm, for example. The top surface of the protrusion on which the substrate W is supported defines a support surface 20. There are protrusions to reduce the surface area in contact with the substrate W when the substrate W is placed on the substrate table WT. Each contact point is a potential source of contamination, and reducing the total contact area reduces the potential for contamination.

  The support 1 is configured to receive the substrate W in a predetermined area on the support surface 20. The predetermined area includes the center 30. In one embodiment, the center 30 receives a substantial center of the substrate W placed on the substrate WT.

  [0042] The predetermined area may be designed to receive a relatively large width or size substrate W, for example a circular substrate having a diameter of 450 mm. Such a large size substrate W has a small thickness to width ratio, resulting in reduced bending stiffness. In one embodiment, the predetermined region may be designed to accept a different top view shape and / or different width or size substrate than a 450 mm diameter circular substrate.

  For a substrate W having a particularly low bending rigidity, lifting the substrate W from the support surface 20 using only three e-pins and lowering the substrate W can lead to surface deformation of the substrate W. Surface deformation caused during loading of the substrate W can lead to more stress in the substrate W when the substrate W is clamped to the support 1. Stress in the substrate W when the substrate W is clamped to the support 1 can lead to overlay grid errors. During unloading of the substrate W using three e-pins, the outer edge of the substrate W tends to hang down. The sagging at the outer edge can lead to further wear of the outer region (eg, the outermost protrusion) of the support surface 20 more than anywhere else. Over time, this can lead to focus errors at the edge of the substrate W.

  [0044] Providing the support 1 with more e-pins may be a solution, but this is more support where the support surface 20 having the form of a protrusion is not provided when viewed from above. 1 (because it is not supported by the e-pin when the substrate W is clamped to the support 1). This can lead to non-planarity of the substrate W when the substrate W is clamped to the support 1, thereby leading to overlay errors.

  In the embodiment of FIG. 2, a surface area greater than the e-pin is provided to support the substrate W during movement to / from the support surface 20. In order to reduce the gap in the support surface 20 (provided by the protrusions) that would otherwise occur, the movable part 50 of the support 1 is a surface that forms the movable part of the support surface 20 (protrusion 55). Of the top). The movable part of the support surface 20 is movable relative to the body 22 of the support 1. The substrate W is supported by the movable part of the support surface 20 during unloading and loading of the substrate W. In one embodiment, the movable part of the support surface 20 supports the substrate W when the substrate W is further supported by the rest of the support surface 20 during imaging. The remainder of the support surface 20 is the main part of the support surface and is immobile with respect to the body 22 of the support 1.

  [0046] As illustrated with reference to FIGS. 3 and 4, the movable portion 50, and thus the movable portion of the support surface 20, is movable relative to the body 22. The movable portion 50 includes a contracted position where the movable portion of the support surface 20 is at or below the major portion of the support surface 20 and an extended position where the movable portion of the support surface 20 protrudes from the major portion of the support surface 20. It is possible to move between. In one embodiment, in the retracted position, the upper end of the protrusion 55 on the movable portion 50 (ie, the movable portion of the support surface 20) is substantially flush with the main portion (eg, the remainder) of the support surface 20. .

  [0047] The movable part 50 having a ring shape as shown in FIG. 2 may be operated at, for example, three positions arranged at equal intervals along the outer periphery thereof. While the elongate member 57 (shown in FIG. 5) is used to actuate the movable part 50 at three individual locations, the movable part 50 between the individual locations has a cross section close to a square (as shown in FIG. 5). No elongated portion 57).

  [0048] As shown in FIG. 2, the movable portion 50 is elongated and is disposed so as to form a multi-sided side as viewed from above. This is in contrast to an e-pin that is not elongated and does not form a polyhedral side, but forms a (triangular) corner. In one embodiment, the polyhedron has at least eight side surfaces, and the closer to a circle, the less deformation that occurs in the substrate W. In the embodiment as shown in FIG. 2, the movable part 50 is arranged in a substantially circular shape (ie, an infinite side shape). In one embodiment, the movable portion 50 is a complete shape that is substantially free of gaps. In one embodiment, the movable part 50 is annular. The advantages are improved support of the substrate W and less bending during loading / unloading.

  [0049] In one embodiment, the movable part 50 may include more than one movable part. For example, the movable portion 50 of FIG. 2 may be separated into a plurality of separate (optionally separate) movable segments. In that case, each movable part 50 may have an arc shape when viewed from above. Alternatively or in addition, the at least one movable part may be provided by a plurality of elongated (eg, linear) movable parts. The movable part 50 may be separated by a gap 59 as illustrated in FIG. 8 described below.

  [0050] In one embodiment, the radial position of the movable part 50 relative to the center 30 is selected for the best support of the substrate W and the minimum bend due to its own weight. In one embodiment, the size of the area of the support surface 20 inside the movable part 50 is substantially equal to the size of the area of the support area 20 outside the movable part 50. Some changes from this rule are possible, but the fewer changes are better. For example, the inner and outer regions are within 20% of each other, desirably within 10% of each other, and more desirably within 5%.

  [0051] In one embodiment, in order to reduce or minimize the size and weight of the movable part 50, the movable part 50 is movable with a width of only one bar (projection 55), as shown in FIG. Having a surface. However, the width of a single bar may not be sufficient to fully support the substrate W, and in one embodiment, the width (radial) of the movable portion 50 is the width of at least two bars (projections 55). It may be. In one embodiment, the movable portion 50 is 5 or less bar wide in the radial direction. If there are more than five bars, the size and weight of the movable part 50 can be so large that the mechanism for moving the movable part 50 may not be well accommodated in the substrate table WT.

  [0052] In one embodiment, the area seen from above the movable part 50 compared to the entire area seen from above the support surface 20 is at least 0.3%, at least 0.5% or at least 0.8%. It is. Thus, the area of support is significantly larger than that of the art (e-pins in the art have an area of about 0.1% of the area of support surface 20). As a result, deformation can be significantly reduced.

  [0053] In one embodiment, for a 300 mm diameter substrate, the movable part 50 will have a diameter of 170 mm +/- 40 mm. For a 450 mm diameter substrate, the movable part 50 will have a diameter of about 255 mm +/− 50 mm. The movable part 50 will be about 5 mm wide (generally 2 mm to 20 mm wide).

  FIG. 3 shows the movable part 50 in a contracted state in which the upper end (the upper end of the protrusion 55 (or the movable part of the support surface)) supports the substrate W. The upper end of the movable part 50 includes the movable part of the support surface 20.

  [0055] In one embodiment, the plurality of movable parts 50 can be actuated individually. In one embodiment, the plurality of movable parts 50 operate together. In one embodiment, the plurality of movable parts 50 are positioned at the same radial distance from the center 30.

  [0056] In one embodiment, the position of the movable part 50 in the retracted position is passively controlled. For example, in one embodiment, the position of the movable part 50 is controlled by a joint between the movable part 50 and the body 22 (eg, by a seal 60 as shown in FIG. 3), thereby allowing the movable part 50 to move. The top surface is substantially flush with the support surface 20.

  [0057] In one embodiment, the position of the movable member 50 is actively controlled in the retracted position. In one embodiment, a positioning device, sensor and controller are provided for that purpose. For example, active servo positioning can be used to control the position of the movable part 50 so that its top surface is substantially in the same plane as the support surface 20. In one embodiment, active control is achieved by a joint (eg, a seal 60) of the movable part 50 with the piezoelectric element.

  In one embodiment, the movable part 50 is made of the same material as the body 22. In one embodiment, the material of the movable part 50 is SiSiC.

  In FIG. 4, the movable part 50 is in an extended position during loading or unloading of the substrate W. In this position, the substrate W is supported only by the movable part of the support surface 20.

  [0060] In one embodiment, the movable part 50 may be provided with one or more heaters and / or coolers to thermally regulate the movable part 50. As can be seen from FIG. 3, the movable part 50 is separated from the rest of the support 1 (ie the body 22). Therefore, the movable part 50 is thermally separated from the rest of the support 1. As a result, the movable member 50 can have a different temperature than the rest of the support 1. This can lead to undesired heat transfer to / from the substrate W through the movable part of the support surface 20, thereby leading to local heating or cooling of the substrate W. Such local heating or cooling of the substrate W can lead to overlay errors. In one embodiment, one or more heaters and / or coolers are provided on the movable part 50. One or more heaters and / or coolers apply a thermal load to the movable part 50 to bring the temperature of the movable part 50 to a temperature substantially equal to the temperature of the rest of the support 1 (eg, the body 22). Controlled to remove. In this way, the local heating / cooling effect achieved through heat transfer through the movable part of the support surface 20 can be reduced, minimized or avoided. In one embodiment, for the same purpose, a conduit is provided in the movable part 50 for a passage through which the temperature-controlled fluid passes.

  [0061] The support 1 may clamp the substrate in a suitable position on the support surface 20. This may be done in any way. The embodiment of FIG. 3 shows how this can be achieved using a vacuum. A negative pressure is generated in a space between the substrate W, the protrusion, and the upper surface 25 of the main body 22 of the support 1. Since the movable part 50 is separate from the body 22 of the support 1, the gap between the movable part 50 and the body 22 is sealed when the movable part 50 is in the retracted position. This can be accomplished by providing a seal 60 that is affixed to one or the other between the movable part 50 and the body 22. The seal 60 may be a non-contact seal. The non-contact seal means that there is a small gap (several μm) between the seal 60 and the movable part 50 even in the contracted position. The seal 60 provides a resistance to the gas path between the movable part 50 and the body 22 so that a negative pressure can be created and maintained between the substrate W and the top surface 25 of the body. The distance between the seal 60 and the movable part 50 is kept small (on the order of 1 or 2 μm), which means that an adequate level of vacuum can still be achieved in the space between the substrate W and the top surface 25 of the body 22 and the bar. Help to ensure. Non-contact seal 60 has the advantage of not imposing position on the movable part 50 and / or minimizing contamination sensitivity. Contamination of the contact seal can lead to inaccuracies in the position of the movable part 50.

  [0062] If the support 1 is an electrostatic clamp, the seal 60 need not be provided, but there may be a seal as a positioning feature (passive or active) for the movable part 50. It may be desirable to help to provide an electrostatic clamping force between the movable part 50 and the substrate W to ensure clamping uniformity and / or clamping during loading and unloading. This can be accomplished in the same way everywhere on the body 22. An example of how this is achieved is shown in FIG.

  [0063] It may be desirable for a clamping force to be applied between the substrate W and the movable part 50 when the movable part 50 is in the extended position or any other position. Further, as described above, it is significant that a force is applied between the movable part 50 and the substrate W even when the movable part 50 is in the contracted position, particularly when the support 1 is an electrostatic clamp support. It can be. In this case, the method of achieving the force between the movable part 50 and the substrate W as shown in FIG. 7 is used at both the contracted and extended positions of the movable part 50 and any position between the two positions. can do.

  FIGS. 5 and 6 illustrate how a clamping force can be applied between the movable part 50 and the substrate W in the extended position (and any other position) relative to the vacuum clamp. This is accomplished by providing a ridge 70 on the movable part 50. The ridge 70 has a lower upper surface than the movable part of the support surface 20 (ie, the upper portion of the protrusion 55). In this way, there is no contact between the ridge 70 and the substrate W. An opening 71 is provided in fluid contact with the region enclosed by the ridge 70. A vacuum source, such as a chamber 72 formed in the body of the movable part 50, is connected to a negative pressure source through a conduit 73 in the elongated member 57. In this way, a negative pressure between the ridge 70 and the substrate W can be generated to draw the substrate W toward the movable part 50. As shown in FIG. 2 and in more detail in FIG. 6, a ridge 70 may be present instead of a bar (protrusion), and the bar is present in the place where the ridge 70 is not present. For this reason, only a few ridges 70 may be provided around the polyhedron. The ridges 70 do not contact the substrate W to avoid contamination and the non-planarity that can be caused thereby. An elongate member 57 (e.g., three, some on the outer periphery of the movable part 50) is used to move the movable part 50 and provide a conduit 73.

  FIG. 7 shows how attractive force can be provided between the movable part 50 in the electrostatic support 1 and the substrate W. In this embodiment, the electrode 80 is provided between the dielectric layer 82 and the insulator layer 84 in the movable part 50. The electrode 80 may have a positive or negative voltage so that a clamping force is generated between the substrate W and the electrode 80, thereby drawing the substrate W onto the movable part 50.

  [0066] In one embodiment, a clamping force between the substrate W and the movable part 50 is applied during loading and unloading of the substrate W. A controller 100 may be provided to activate / deactivate the clamping force.

  [0067] FIG. 8 shows an embodiment that is the same as the embodiment of FIG. 2 except as described below. Embodiments where all or only some differences between the embodiments of FIGS. 2 and 8 are implemented are possible.

  [0068] In one embodiment, a plurality of one or more additional movable parts 150 may be provided. The movable part 150 may be the same as the e-pin from the viewpoint of not contacting the substrate W in the contracted position, or may be the same as the movable part 50 described above. In one embodiment, the additional movable part 150 is a plurality of separate movable parts 150. The further movable part 150 may be positioned radially inwardly, radially outwardly or both of the movable part 50.

  [0069] In one embodiment, there are a plurality of movable parts 50. The movable part 50 may be elongated. As shown in FIG. 8, in one embodiment, the plurality of movable parts 50 may form a polyhedral side. The plurality of movable parts 50 may form segments of that shape. There may be a gap 59 between adjacent movable parts 50. In order for the presence of the gap 59 not to result in the bending of the substrate W, in one embodiment, the total length of the gap 59 between adjacent movable parts 50 in a polyhedral shape is formed by a plurality of movable parts 50 when viewed from above. Less than 50% of the polyhedral perimeter to be done.

  [0070] The support 1 may form part of the substrate table WT. Such a substrate table WT may be used in a lithographic apparatus, for example a projection lithographic apparatus.

  [0071] A lithographic apparatus comprising a support 1 according to an embodiment of the invention may comprise a substrate handler 600 for loading and / or unloading a substrate onto the support 1. Such a substrate handler 600 may have two arms that support the substrate W from below. The arm can support the substrate W in a region outside the movable part 50 when the substrate W is loaded on the support. In addition or alternatively, one or more arms of the substrate handler 600 can support the substrate W at a radius that is equal to or less than the position of the movable portion 50. This is the case in the embodiment of FIG. 8 if the arm of the substrate handler 600 can be inserted between the movable part 50 and the movable part 50 through the gap 59 and / or one or more movable parts. This can be achieved when the 50 is moved from the extended position and the lower arm of the substrate W can be put in place.

  [0072] In one embodiment, the substrate handler 600 can handle a substrate from above. In one embodiment, the substrate handler 600 can handle the substrate from the top at the edge of the substrate. In one embodiment, the holding mechanism of the substrate handler 600 may comprise a plurality of brackets arranged to support the substrate W along the edge of the substrate W. In such an embodiment, the bracket may be arranged to move outward and inward to remove and remove the substrate W. In order to allow such displacement, the holder may be provided with one or more actuators, such as piezoelectric or electromagnetic actuators. Such embodiments are described in US Patent Application No. US 61 / 552,282, filed Oct. 27, 2011, which is hereby incorporated by reference in its entirety.

  [0073] In one aspect, a support for an object is provided that includes a support surface configured to support the object. The support surface includes a main portion and a movable portion, the movable portion of the support surface being movable between a retracted position and an extended position, wherein the movable portion of the support surface is in contact with the main portion of the support surface. Adapted to be in substantially the same plane, in the extended position, the movable part of the support surface protrudes from the plane of the main part of the support surface.

  [0074] In one embodiment, the movable part of the support surface is the upper end of the movable part.

  [0075] In one embodiment, the movable parts of the support surface are arranged to form a multi-sided side as viewed from above.

  [0076] In one aspect, a support for an object, disposed to form a support surface configured to support the object, and a multi-sided side view from above, and in a contracted position and extended. An elongate movable part that is movable between a position and in the retracted position, the upper end of the movable part is adapted to be at or below the plane of the main part of the support surface, and in the extended position A support is provided that includes an elongate movable part, the upper end of the movable part protruding from the plane of the main part of the support surface.

  [0077] In one embodiment, in the retracted position, the upper end of the movable part is adapted to form a movable part of the support surface and to be substantially in the same plane as the main part of the support surface including the rest of the support surface Is done.

  [0078] In one embodiment, the polyhedron comprises at least eight sides.

  [0079] In one embodiment, the polyhedron is substantially circular.

  [0080] In one embodiment, the polyhedron is a substantially gapless full shape.

  [0081] In one embodiment, the polyhedron is formed by a plurality of movable segments.

  [0082] In one embodiment, the segments are separated by gaps, and the total gap length between adjacent segments is less than 50% of the perimeter of the polyhedron.

  [0083] In one embodiment, each movable part has an arcuate shape when viewed from above.

  [0084] In one embodiment, the support surface is formed from a plurality of upper ends of individual protrusions.

  [0085] In one embodiment, the movable part is smaller than the width of the five protrusions, smaller than the width of the three protrusions, smaller than the width of the two protrusions, or one width of the protrusion.

  [0086] In one embodiment, the movable part comprises a lower ridge than the protrusion.

  [0087] In one embodiment, the support further comprises a conduit that is in fluid communication with the region surrounded by the ridge and is connectable to a negative pressure source.

  [0088] In one embodiment, the movable part is elongated when viewed from above.

  [0089] In one embodiment, the movable part is positioned at a constant radial distance from the center of the support surface.

  [0090] In one embodiment, the movable part is positioned such that the size of the area of the support surface enclosed by the movable part is within 20% of the size of the area of the support surface not enclosed by the movable part.

  [0091] In one embodiment, the area of the movable part viewed from above is at least 0.3% of the area of the support surface viewed from above, at least 0.5% of the area of the support surface viewed from above or from above. At least 0.8% of the area of the support surface seen.

  [0092] In one embodiment, the support further comprises a seal for resisting the passage of gas between the movable part and the support surface when the movable part is in the retracted position.

  [0093] In one embodiment, the support further comprises a heater and / or cooler that heats and / or cools the movable part.

  [0094] In one embodiment, the support further comprises a further movable part positioned at a radial distance from the center of the support surface that is different from the movable part.

  [0095] In one embodiment, the support is configured to clamp the object to the support surface using negative pressure.

  [0096] In one embodiment, the support is configured to clamp the object to the support surface using electrostatic forces.

  [0097] In an embodiment, the support is configured to support a substrate in the lithographic apparatus.

  [0098] In one embodiment, the support further comprises a controller configured to actively position the movable part when in the retracted position.

  [0099] In one aspect, a lithographic apparatus is provided that includes the support described above.

  [00100] In an embodiment, the lithographic apparatus further comprises a handler for positioning an object on the support surface.

  [00101] In one embodiment, the handler is arranged to grab the object from above.

  [00102] In one embodiment, the handler is configured to grip the object at its end.

  [00103] In one aspect, a device manufacturing method is provided that includes projecting a patterned beam of radiation onto a substrate supported by a support surface. The support surface comprises a main part and a movable part, the movable part of the support surface being movable between a retracted position and an extended position, wherein the movable part of the support surface is separated from the main part of the support surface. Adapted to be in substantially the same plane, in the extended position, the movable part of the support surface protrudes from the plane of the main part of the support surface.

  [00104] Although specific reference is made herein to the use of a lithographic apparatus in IC manufacturing, the lithographic apparatus described herein is an integrated optical system, a guidance pattern and a detection pattern for a magnetic domain memory, It should be understood that other applications such as the manufacture of flat panel displays, liquid crystal displays (LCDs), thin film magnetic heads and the like may be had. As will be appreciated by those skilled in the art, in such other applications, the terms “wafer” or “die” as used herein are all more general “substrate” or “target” respectively. It may be considered synonymous with the term “part”. The substrate described herein can be used, for example, before or after exposure, such as a track (usually a tool for applying a resist layer to the substrate and developing the exposed resist), a metrology tool, and / or an inspection tool. May be processed. Where applicable, the disclosure herein may be applied to substrate processing tools such as those described above and other substrate processing tools. Further, since the substrate may be processed multiple times, for example, to make a multi-layer IC, the term substrate as used herein may refer to a substrate that already contains multiple processing layers.

  [00105] While specific reference has been made to the use of embodiments of the present invention in the context of optical lithography as described above, it will be appreciated that the present invention may be used in other applications, such as imprint lithography. However, it is not limited to optical lithography if the situation permits. In imprint lithography, the topography within the patterning device defines the pattern that is created on the substrate. The topography of the patterning device is pressed into a resist layer supplied to the substrate, whereupon the resist is cured by electromagnetic radiation, heat, pressure, or a combination thereof. The patterning device is moved out of the resist leaving a pattern in it after the resist is cured.

  [00106] The terms "radiation" and "beam" as used herein refer to ultraviolet (UV) (eg, wavelengths of 436 nm, 405 nm, 365 nm, 355 nm, 248 nm, 193 nm, 157 nm, or 126 nm, or approximately these And all kinds of electromagnetic radiation including extreme ultraviolet (EUV) (e.g. having a wavelength in the range of 5-20 nm), and particle beams such as ion beams and electron beams. .

  [00107] While specific embodiments of the invention have been described above, it will be appreciated that the invention may be practiced otherwise than as described. For example, embodiments of the invention may be in the form of a computer program that includes a sequence of one or more machine-readable instructions that represent the methods disclosed above, or a data storage medium (eg, a semiconductor) that stores such a computer program. It may be in the form of a memory, magnetic disk or optical disk. Further, the machine readable instructions can be implemented by two or more computer programs. Two or more computer programs may be stored in one or more different memories and / or data storage media.

  [00108] One embodiment of the invention may be applied to a substrate having a diameter of 300 mm, 450 mm, or any other size.

  [00109] Any controller described herein is a controller or controller when one or more computer programs are read by one or more computer processors located in at least one component of the lithographic apparatus. Any controller combination can operate. Each controller or combination thereof may have any suitable configuration for receiving, processing and transmitting signals. The one or more processors are configured to communicate with at least one controller. For example, each controller may include one or more processors for executing a computer program that includes machine-readable instructions for the methods described above. The controller may include one or more data storage media for storing such computer programs and / or hardware for accepting such one or more media. Thus, the controller (s) may operate according to machine readable instructions of one or more computer programs.

  [00110] One or more embodiments of the present invention provide for any immersion liquid regardless of whether the immersion liquid is provided in the form of a solution bath, or only on the local surface area of the substrate, or in an unconfined state. It can be applied to an immersion lithography apparatus. In an unconfined configuration, immersion liquid may flow over the surface of the substrate and / or substrate table, thereby wetting the substantially uncovered surface of the substrate table and / or substrate. In such an unconfined immersion system, the liquid supply system may not confine the immersion liquid or may provide a portion of the immersion liquid confinement but not substantially complete confinement of the immersion liquid. .

  [00111] In an embodiment, the lithographic apparatus is a multi-stage apparatus comprising two or more tables arranged on the exposure side of the projection system, each table comprising and / or holding one or more objects. In one embodiment, one or more tables may hold a radiation sensitive substrate. In one embodiment, one or more tables may hold sensors to measure radiation from the projection system. In one embodiment, the multi-stage apparatus includes a first table configured to hold a radiation sensitive substrate (i.e., a substrate table) and a second table not configured to hold a radiation sensitive substrate ( Hereinafter, it is usually referred to as a measurement and / or cleaning table but is not limited thereto). The second table may comprise and / or hold one or more objects other than the radiation sensitive substrate. Such one or more objects include one or more selected from a sensor that measures radiation from the projection system, one or more alignment marks, and / or a cleaning device (eg, to clean a liquid confinement structure). It may be a thing.

  [00112] In an embodiment, the lithographic apparatus may comprise an encoder system for measuring the position, velocity, etc. of the components of the apparatus. In one embodiment, the component comprises a substrate table. In one embodiment, the component comprises a measurement and / or cleaning table. The encoder system may be in addition to or in place of the interferometer system for the table described herein. The encoder system comprises a sensor, transducer or readhead associated with (eg, combined with) a scale or grid. In one embodiment, the movable component (e.g., substrate table and / or measurement and / or cleaning table) has one or more scales or grids, and the frame in which the component moves relative to the frame of the lithographic apparatus is It has one or more sensors, transducers or read heads. One or more sensors, transducers or readheads cooperate with the (one or more) scale and (one or more) grid to determine the position, velocity, etc. of the component. In one embodiment, the frame in which the component moves relative to the frame of the lithographic apparatus has one or more scales or grids, and the movable component (eg, substrate table and / or measurement and / or cleaning table) is (1 It has one or more sensors, transducers or read heads that cooperate with one or more scales or grid (s) to determine component position, velocity, etc.

  [00113] The term "lens" refers to any one or combination of various types of optical components, including refractive, reflective, catadioptric, magnetic, electromagnetic, and electrostatic optical components, depending on the context. be able to.

  [00114] The descriptions above are intended to be illustrative, not limiting. Thus, it will be apparent to one skilled in the art that modifications may be made to the invention as described without departing from the scope of the claims set out below.

Claims (15)

Support for objects,
A support surface for supporting the object;
The support surface includes a main portion and a movable portion, the movable portion of the support surface being movable between a retracted position and an extended position, wherein the movable portion of the support surface is in the retracted position. A support that is in substantially the same plane as the main portion of the support surface, and in the extended position, the movable portion of the support surface protrudes from the plane of the main portion of the support surface.   The support according to claim 1, wherein the movable part of the support surface is an upper end of the movable part and / or forms a polyhedral side as viewed from above. Support for objects,
A support surface that supports the object;
An elongate movable part that forms a polyhedral side when viewed from above and is movable between a contracted position and an extended position, wherein the upper end of the movable part is the main part of the support surface. A support comprising: an elongate movable portion that is in or below the plane of the portion and, in the extended position, the upper end of the movable portion protrudes from the plane of the main portion of the support surface.   4. In the retracted position, the upper end of the movable part forms a movable part of the support surface and is substantially in the same plane as the main part of the support surface including the rest of the support surface. Support described in.   The polyhedron includes at least eight sides and / or the polyhedron is substantially circular and / or the polyhedron is a substantially gapless full shape and / or the polyhedron A support according to any of claims 2 to 4, wherein the shape is formed by a plurality of movable segments.   The support according to claim 5, wherein the segments are separated by gaps, and the total gap length between adjacent segments is less than 50% of the outer perimeter of the polyhedron.   The support according to claim 1, wherein each movable part has an arc shape when viewed from above.   The support surface is formed from a plurality of upper ends of individual protrusions and / or the support uses negative pressure to clamp the object to the support surface and / or the support uses electrostatic force. Support according to any of the preceding claims, wherein the object is clamped to the support surface and / or the support supports a substrate in a lithographic apparatus.   The movable part is smaller than the width of the protrusions 5, smaller than the width of the protrusions 3, smaller than the width of the protrusions 2, or one width of the protrusions, and / or the movable part is smaller than the width of the protrusions Comprising a low ridge and / or the movable part is elongated when viewed from above and / or the movable part is positioned at a constant radial distance from the center of the support surface and / or the movable part is Positioned such that the size of the area of the support surface enclosed by the movable part is within 20% of the size of the area of the support surface not enclosed by the movable part and / or viewed from above The region of the movable part is at least 0.3% of the region of the support surface viewed from above, and at least 0.5% of the region of the support surface viewed from above Is at least 0.8% of the area of the support surface as viewed from above Taha, support according to claim 8.   Further comprising a conduit in fluid communication with the region surrounded by the ridge and connectable to a negative pressure source and / or between the movable part and the support surface when the movable part is in the retracted position A seal that resists the passage of gas and / or a heater and / or cooler that heats and / or cools the movable part and / or a center of the support surface that is different from the movable part The support according to claim 9, further comprising a further movable part positioned at a radial distance from and / or a controller for actively positioning the movable part when in the retracted position.   A lithographic apparatus, comprising the support according to claim 1.   The lithographic apparatus according to claim 11, further comprising a handler for positioning the object on the support surface.   The lithographic apparatus according to claim 12, wherein the handler grabs the object from above.   The lithographic apparatus according to claim 12 or 13, wherein the handler grips the object at an end thereof. A device manufacturing method comprising:
Projecting a patterned beam of radiation onto a substrate supported by a support surface;
The support surface includes a main portion and a movable portion, the movable portion of the support surface being movable between a retracted position and an extended position, wherein the movable portion of the support surface is in the retracted position. A device manufacturing method, wherein the device is in substantially the same plane as the main part of the support surface, and in the extended position, the movable part of the support surface protrudes from the plane of the main part of the support surface.

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